Luminaires with automated and remotely controllable functionality are well known in the entertainment and architectural lighting markets. Such products are commonly used in theatres, television studios, concerts, theme parks, night clubs, and other venues. A typical product will provide control over the functions of the luminaire allowing the operator to control the intensity and color of the light beam from the luminaire that is shining on the stage or in the studio. Many products also provide control over other parameters such as the position, focus, beam size, beam shape, and beam pattern. In such products that contain light emitting diodes (LEDs) to produce the light output it is common to use more than one color of LEDs and to be able to adjust the intensity of each color separately such that the output, which comprises the combined mixed output of all LEDs, can be adjusted in color. For example, such a product may use red, green, blue, and white LEDs with separate intensity controls for each of the four types of LED. This allows the user to mix almost limitless combinations and to produce nearly any color they desire.
FIG. 1 illustrates a typical multiparameter automated luminaire system 10. These systems typically include a plurality of multiparameter automated luminaires 12 which typically each contain on-board a light source (not shown), light modulation devices, electric motors coupled to mechanical drive systems, and control electronics (not shown). In addition to being connected to mains power either directly or through a power distribution system (not shown), each automated luminaire 12 is connected in series or in parallel to data link 14 to one or more control desks 15. The automated luminaire system 10 is typically controlled by an operator through the control desk 15.
Luminaires have been provided using non-LED light sources designed to produce a single narrow beam or a plurality of such beams. Such luminaires may use low etendue, High Intensity Discharge (HID) light sources with a small arc gap in order to facilitate the production of tight, almost parallel light beams. U.S. patent application Ser. Nos. 14/042,758 and 14/042,759 provide examples of such a system. Single and multi-color LED sourced luminaires have also been produced with narrow beam capability using sophisticated collimation systems as, for example, disclosed in U.S. patent application Ser. No. 14/405,355. LEDs however are high etendue light sources by comparison with HID and it is difficult to produce multiple separated beam systems using LED light sources.
Prior art optical systems utilizing multiple LED emitters designed to be run independently as separate light modules within a single luminaire frequently suffer from light spill from one light module to the adjacent light module. This light spill contaminates the effect and clarity of each of the independent light modules and reduces the effectiveness of the luminaire for both the user and the viewer. Independent light modules should be truly independent with minimal spill of light from one light module to adjacent light module(s). Prior art systems may use internal baffles or egg-crates to try and isolate the independent light sources, but still suffer from light spill or bleeding across adjacent light modules due to internal reflection, back reflection, refraction, or other light leakage path(s). These prior art systems may also reduce the performance of the luminaire by restricting the output apertures in an attempt to provide light isolation.
There is a need for a method for producing and controlling the light spill between adjacent modules from an LED sourced wash light luminaire producing multiple light beams.